What is CVE-2017-18403?

CVE-2017-18403 is a medium-severity vulnerability in Cpanel, classified under Improper Access Control. CVSS score: 6.3/10. Published 2019-08-02.

How severe is CVE-2017-18403?

Medium severity. CVSS v3 base score is 6.3 out of 10.

Vulnerability in Cpanel

CVE-2017-18403

cPanel before 68.0.15 allows code execution in the context of the nobody account via Mailman archives (SEC-337).

Published 2019-08-02 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.3 (Medium). Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L.

EPSS exploit prediction

EPSS: 0.008 (55.9th percentile), scored 2026-09-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 56th percentile — 55.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.008 · newest: 0.008 · change: 0.000

Affected products

Cpanel

Weakness classification (CWE)

CWE-284 — Improper Access Control

References

documentation.cpanel.net/display/CL/68+Change+Log (Product, Release Notes)
news.cpanel.com/cpanel-tsr-2017-0006-full-disclosure/ (Vendor Advisory)

Frequently asked questions

What is CVE-2017-18403?: CVE-2017-18403 is a medium-severity vulnerability in Cpanel, classified under Improper Access Control. CVSS score: 6.3/10. Published 2019-08-02.
How severe is CVE-2017-18403?: Medium severity. CVSS v3 base score is 6.3 out of 10.